EGF-induced redistribution of erbB2 on breast tumor cells: flow and image cytometric energy transfer measurements.
AuthorsNagy P, Bene L, Balázs M, Hyun WC, Lockett SJ, Chiang NY, Waldman F, Feuerstein BG, Damjanovich S, Szöllosi J
JournalCytometry
PubMed ID9627225
erbB2, a member of the epidermal growth factor (EGF) receptor-type tyrosine kinase receptor family, is overexpressed in breast carcinomas with poor prognosis. We examined the cell surface association of this receptor with itself and with other cell surface proteins by the Förster-type fluorescence resonance energy transfer using whole antibodies and ... More
Bid, a widely expressed proapoptotic protein of the Bcl-2 family, displays lipid transfer activity.
AuthorsEsposti MD, Erler JT, Hickman JA, Dive C
JournalMol Cell Biol
PubMed ID11585909
'Bid is an abundant proapoptotic protein of the Bcl-2 family that is crucial for the induction of death receptor-mediated apoptosis in primary tissues such as liver. Bid action has been proposed to involve the relocation of its truncated form, tBid, to mitochondria to facilitate the release of apoptogenic cytochrome c. ... More
Intracellular transport of phosphatidic acid and phosphatidylcholine into lipid bodies in an oleaginous fungus, Mortierella ramanniana var. angulispora.
AuthorsKamisaka Y, Noda N
JournalJ Biochem (Tokyo)
PubMed ID11134953
'Exogenous fluorescent phosphatidic acid (PA) and phosphatidylcholine (PC) were transported into lipid bodies in an oleaginous fungus, Mortierella ramanniana var. angulispora [Kamisaka et al. (1999) Biochim. Biophys. Acta 1438, 185-198]. We further investigated the processes of fluorescent PA and PC transport into lipid bodies in this fungus by changing culture ... More
Characterization of Ca2+-dependent phospholipase A2 activity during zebrafish embryogenesis.
AuthorsFarber SA, Olson ES, Clark JD, Halpern ME
JournalJ Biol Chem
PubMed ID10383445
'We have developed a simple fluorescent assay for detection of phospholipase A2 (PLA2) activity in zebrafish embryos that utilizes a fluorescent phosphatidylcholine substrate. By using this assay in conjunction with selective PLA2 inhibitors and Western blot analysis, we identified the principal activity in zebrafish embryogenesis as characteristic of the Ca2+-dependent ... More
Coexisting stripe- and patch-shaped domains in giant unilamellar vesicles.
AuthorsLi L, Cheng JX
JournalBiochemistry
PubMed ID17002282
'We report a new type of gel-liquid phase segregation in giant unilamellar vesicles (GUVs) of mixed lipids. Coexisting patch- and stripe-shaped gel domains in GUV bilayers composed of DOPC/DPPC or DLPC/DPPC are observed by confocal fluorescence microscopy. The lipids in stripe domains are shown to be tilted according to the ... More
Measurement of spontaneous transfer and transbilayer movement of BODIPY-labeled lipids in lipid vesicles.
AuthorsBai J, Pagano RE
JournalBiochemistry
PubMed ID9220970
'An assay was developed to study the spontaneous transfer and transbilayer movement (flip-flop) of lipid analogs labeled with the fluorescent fatty acid, 5-(5,7-dimethyl BODIPY)-1-pentanoic acid (C5-DMB-) in large unilamellar lipid vesicles comprised of 1-palmitoyl-2-oleoyl phosphatidylcholine (POPC). The assay is based on the concentration-dependent changes in fluorescence intensity that occur when ... More
Novel Fusogenic Liposomes for Fluorescent Cell Labeling and Membrane Modification.
AuthorsCsisza´r A, Hersch N, Dieluweit S, Biehl R, Merkel R, Hoffmann B,
JournalBioconjug Chem
PubMed ID20184308
'Efficient delivery of biomolecules into membranes of living cells as well as cell surface modifications are major biotechnological challenges. Here, novel liposome systems based on neutral and cationic lipids in combination with lipids modified by aromatic groups are introduced for such applications. The fusion efficiency of these liposome systems was ... More
Vascular lipid accumulation, lipoprotein oxidation, and macrophage lipid uptake in hypercholesterolemic zebrafish.
AuthorsStoletov K, Fang L, Choi SH, Hartvigsen K, Hansen LF, Hall C, Pattison J, Juliano J, Miller ER, Almazan F, Crosier P, Witztum JL, Klemke RL, Miller YI,
JournalCirc Res
PubMed ID19265037
'Lipid accumulation in arteries induces vascular inflammation and atherosclerosis, the major cause of heart attack and stroke in humans. Extreme hyperlipidemia induced in mice and rabbits enables modeling many aspects of human atherosclerosis, but microscopic examination of plaques is possible only postmortem. Here we report that feeding adult zebrafish (Danio ... More
Vesicular and nonvesicular transport of phosphatidylcholine in polarized HepG2 cells.
AuthorsWüstner D, Mukherjee S, Maxfield FR, Müller P, Herrmann A
JournalTraffic
PubMed ID11285138
'We have investigated the transport and canalicular enrichment of fluorescent phosphatidylcholine (PC) in HepG2 cells using the fluorescent analogs of PC C6-NBD-PC and beta-BODIPY-PC. Fluorescent PC was efficiently transported to the biliary canaliculus (BC) and became enriched on the lumenal side of the canalicular membrane as shown for C6-NBD-PC. Some ... More
Differential partitioning of maternal fatty acid and phospholipid in neonate mosquito larvae.
AuthorsAtella GC, Shahabuddin M
JournalJ Exp Biol
PubMed ID12409488
'In animals, lipids are a source of energy, cell membrane components, signaling pathway modulators and emulsifying agents. In egg-laying animals, maternal yolk lipids, imported into the egg before laying, are metabolized or distributed in the developing embryo to serve these functions. Studies with birds, reptiles and insects have described lipid ... More
Flippase activity detected with unlabeled lipids by shape changes of giant unilamellar vesicles.
AuthorsPapadopulos A, Vehring S, López-Montero I, Kutschenko L, Stöckl M, Devaux PF, Kozlov M, Pomorski T, Herrmann A
JournalJ Biol Chem
PubMed ID17369612
'Transbilayer movement of phospholipids in biological membranes is mediated by energy-dependent and energy-independent flippases. Available methods for detection of flippase mediated transversal flip-flop are essentially based on spin-labeled or fluorescent lipid analogues. Here we demonstrate that shape change of giant unilamellar vesicles (GUVs) can be used as a new tool ... More
Genetic analysis of digestive physiology using fluorescent phospholipid reporters.
AuthorsFarber SA, Pack M, Ho SY, Johnson ID, Wagner DS, Dosch R, Mullins MC, Hendrickson HS, Hendrickson EK, Halpern ME
JournalScience
PubMed ID11359013
'Zebrafish are a valuable model for mammalian lipid metabolism; larvae process lipids similarly through the intestine and hepatobiliary system and respond to drugs that block cholesterol synthesis in humans. After ingestion of fluorescently quenched phospholipids, endogenous lipase activity and rapid transport of cleavage products results in intense gall bladder fluorescence. ... More
Nanoscale complexity of phospholipid monolayers investigated by near-field scanning optical microscopy.
AuthorsHwang J, Tamm LK, Böhm Ramalingam TS, Betzig E, Edidin M
JournalScience
PubMed ID7570018
'Near-field scanning optical microscopy of phospholipid monolayers doped with fluorescent lipid analogs reveals previously undescribed features in various phases, including a concentration gradient at the liquid-expanded/liquid-condensed domain boundary and weblike structures in the solid-condensed phase. Presumably, the web structures are grain boundaries between crystalline solid lipid. These structures are strongly ... More
Sequence and functional similarities between pro-apoptotic Bid and plant lipid transfer proteins.
AuthorsDegli Esposti M
JournalBiochim Biophys Acta
PubMed ID11997142
'Pro-apoptotic proteins of the Bcl-2 family are known to act on mitochondria and facilitate the release of cytochrome c, but the biochemical mechanism of this action is unknown. Association with mitochondrial membranes is likely to be important in determining the capacity of releasing cytochrome c. The present work provides new ... More
Depth-profiling with giant vesicle membranes.
AuthorsMenger FM, Keiper JS, Caran KL
JournalJ Am Chem Soc
PubMed ID12358515
Lipophilic dye staining of Cryptococcus neoformans extracellular vesicles and capsule.
AuthorsNicola AM, Frases S, Casadevall A,
JournalEukaryot Cell
PubMed ID19465562
Cryptococcus neoformans is an encapsulated yeast that causes systemic mycosis in immunosuppressed individuals. Recent studies have determined that this fungus produces vesicles that are released to the extracellular environment both in vivo and in vitro. These vesicles contain assorted cargo that includes several molecules associated with virulence and implicated in ... More
Novel anti-cholesterol monoclonal immunoglobulin G antibodies as probes and potential modulators of membrane raft-dependent immune functions.
AuthorsBíró A, Cervenak L, Balogh A, Lorincz A, Uray K, Horváth A, Romics L, Matkó J, Füst G, László G,
JournalJ Lipid Res
PubMed ID17023738
Natural autoantibodies against cholesterol are present in the sera of all healthy individuals; their function, production, and regulation, however, are still unclear. Here, we managed to produce two monoclonal anti-cholesterol antibodies (ACHAs) by immunizing mice with cholesterol-rich liposomes. The new ACHAs were specific to cholesterol and to some structurally closely ... More
Novel lipid transfer property of two mitochondrial proteins that bridge the inner and outer membranes.
AuthorsEpand RF, Schlattner U, Wallimann T, Lacombe ML, Epand RM
JournalBiophys J
PubMed ID17028143
This study provides evidence of a novel function for mitochondrial creatine kinase (MtCK) and nucleoside diphosphate kinase (NDPK-D). Both are basic peripheral membrane proteins with symmetrical homo-oligomeric structure, which in the case of MtCK was already shown to allow crossbridging of lipid bilayers. Here, different lipid dilution assays clearly demonstrate ... More
Ternary phase diagram of dipalmitoyl-PC/dilauroyl-PC/cholesterol: nanoscopic domain formation driven by cholesterol.
AuthorsFeigenson GW, Buboltz JT
JournalBiophys J
PubMed ID11371452
A ternary phase diagram is proposed for the hydrated lamellar lipid mixture dipalmitoylphosphatidylcholine/dilauroylphosphatidylcholine/cholesterol (DPPC/DLPC/cholesterol) at room temperature. The entire composition space has been thoroughly mapped by complementary experimental techniques, revealing interesting phase behavior that has not been previously described. Confocal fluorescence microscopy shows a regime of coexisting DPPC-rich ordered and ... More
Diversity in secreted PLA2-IIA activity among inbred mouse strains that are resistant or susceptible to Apc Min/+ tumorigenesis.
AuthorsMarkova M, Koratkar RA, Silverman KA, Sollars VE, MacPhee-Pellini M, Walters R, Palazzo JP, Buchberg AM, Siracusa LD, Farber SA
JournalOncogene
PubMed ID16007193
The secreted phospholipase A2 type IIA (Pla2g2a) gene was previously identified as a modifier of intestinal adenoma multiplicity in Apc Min/+ mice. To determine if intestinal secreted phospholipase A2 (sPLA2) activity was also attenuated in susceptible strains, we developed a sensitive assay to directly quantitate sPLA2 activity in the murine ... More
Intramolecularly quenched BODIPY-labeled phospholipid analogs in phospholipase A(2) and platelet-activating factor acetylhydrolase assays and in vivo fluorescence imaging.
AuthorsHendrickson HS, Hendrickson EK, Johnson ID, Farber SA
JournalAnal Biochem
PubMed ID10585741
Phospholipase substrate analogs containing both a fluorescent BODIPY group and a quenching 2,4-dinitrophenyl (DNP) group were synthesized. They showed little fluorescence, but upon hydrolysis became fluorescent as the quenching group was removed. Two substrates were phosphatidylethanolamine analogs with a BODIPY-pentanoyl group at the sn-2 position and DNP linked to the ... More
Physical and photophysical characterization of a BODIPY phosphatidylcholine as a membrane probe.
AuthorsDahim M, Mizuno NK, Li XM, Momsen WE, Momsen MM, Brockman HL
JournalBiophys J
PubMed ID12202376
Lipids containing the dimethyl BODIPY fluorophore are used in cell biology because their fluorescence properties change with fluorophore concentration (C.-S. Chen, O. C. Martin, and R. E. Pagano. 1997. Biophys J. 72:37-50). The miscibility and steady-state fluorescence behavior of one such lipid, 1-palmitoyl-2-(4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-pentanoyl)-sn-glycero-3-phosphocholine (PBPC), have been characterized in mixtures with ... More
Separation of phospholipids in microfluidic chip device: application to high-throughput screening assays for lipid-modifying enzymes.
AuthorsLin S, Fischl AS, Bi X, Parce W
JournalAnal Biochem
PubMed ID12633607
Phospholipid molecules such as ceramide and phosphoinositides play crucial roles in signal transduction pathways. Lipid-modifying enzymes including sphingomyelinase and phosphoinositide kinases regulate the generation and degradation of these lipid-signaling molecules and are important therapeutic targets in drug discovery. We now report a sensitive and convenient method to separate these lipids ... More
Domains in cell plasma membranes investigated by near-field scanning optical microscopy.
AuthorsHwang J, Gheber LA, Margolis L, Edidin M
JournalBiophys J
PubMed ID9591645
Near-field scanning optical microscopy (NSOM) uses the near-field interaction of light from a sharp fiber-optic probe with a sample of interest to image surfaces at a resolution beyond the diffraction limit of conventional optics. We used NSOM to image fluorescently labeled plasma membranes of fixed human skin fibroblasts, either dried ... More
Release of phospholipids from erythrocyte membranes by taurocholate is determined by their transbilayer orientation and hydrophobic backbone.
AuthorsWüstner D, Pomorski T, Herrmann A, Müller P
JournalBiochemistry
PubMed ID9836604
Bile salts mediate a specific release of phosphatidylcholine (PC) from the canalicular membrane into the bile fluid. We utilized human red blood cells (RBC) as a model system to study the release of endogenous phospholipids as well as phospholipid analogues from plasma membranes in the presence of the bile salt ... More
Purification and analysis of a phospholipase A2-like lytic factor of Trichomonas vaginalis.
AuthorsLubick KJ, Burgess DE
JournalInfect Immun
PubMed ID14977929
Trichomonas vaginalis produces soluble factors that have been reported to have the ability to damage target cells in vitro, and it has been hypothesized that these factors may play a role in the pathogenesis of human trichomoniasis. A lytic factor (LF) was purified from T. vaginalis, and the molecular characteristics ... More
Undifferentiated HL-60 cells internalize an antitumor alkyl ether phospholipid more rapidly than resistant K562 cells.
AuthorsTsutsumi T, Tokumura A, Kitazawa S
JournalBiochim Biophys Acta
PubMed ID9487142
In this study, we confirmed a previous finding that 1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine (methyl-PAF) expresses higher antineoplastic activity against the promyelocytic leukemia cell line HL-60, than against the erythroleukemic cell line K562, and intended to clarify the reason for this. Using an albumin back-exchange method, we measured the rates of binding and internalization ... More
Characterization of lipid bilayer phases by confocal microscopy and fluorescence correlation spectroscopy.
We report the application of confocal imaging and fluorescence correlation spectroscopy (FCS) to characterize chemically well-defined lipid bilayer models for biomembranes. Giant unilamellar vesicles of dilauroyl phosphatidylcholine/dipalmitoyl phosphatidylcholine (DLPC/DPPC)/cholesterol were imaged by confocal fluorescence microscopy with two fluorescent probes, 1, 1'-dieicosanyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate (DiI-C(20)) and 2-(4,4-difluoro-5,7-dimethyl-4-bora-3a, 4a-diaza-s-indacene-3-pentanoyl)-1-hexadecanoyl-sn-glycero-3 -phosphoc holine (Bodipy-PC). Phase ... More
Spontaneous, intervesicular transfer rates of fluorescent, acyl chain-labeled phosphatidylcholine analogs.
AuthorsElvington SM, Nichols JW
JournalBiochim Biophys Acta
PubMed ID17198675
It was recently shown that the structure of the fluorophore attached to the acyl chain of phosphatidylcholine analogs determines their mechanism of transport across the plasma membrane of yeast cells (Elvington et al., J. Biol Chem. 280:40957, 2005). In order to gain further insight into the physical properties of these ... More
Palmitoylation and intracellular domain interactions both contribute to raft targeting of linker for activation of T cells.
AuthorsShogomori H, Hammond AT, Ostermeyer-Fay AG, Barr DJ, Feigenson GW, London E, Brown DA
JournalJ Biol Chem
PubMed ID15753089
Some transmembrane proteins must associate with lipid rafts to function. However, even if acylated, transmembrane proteins should not pack well with ordered raft lipids, and raft targeting is puzzling. Acylation is necessary for raft targeting of linker for activation of T cells (LAT). To determine whether an acylated transmembrane domain ... More
Uptake and compartmentalization of fluorescent lipid analogs in larval Schistosoma mansoni.
AuthorsFurlong ST, Thibault KS, Morbelli LM, Quinn JJ, Rogers RA
JournalJ Lipid Res
PubMed ID7706934
Recent studies have suggested that host lipids are both a requirement for the human parasite Schistosoma mansoni and may play a role in evasion of host immunity. To study lipid utilization by this organism we have followed the uptake of fluorescent fatty acid and phospholipid analogs in two parasite stages, ... More
Lipid bodies and lipid body formation in an oleaginous fungus, Mortierella ramanniana var. angulispora.
AuthorsKamisaka Y, Noda N, Sakai T, Kawasaki K
JournalBiochim Biophys Acta
PubMed ID10320801
Mortierella ramanniana var. angulispora accumulates triacylglycerol (TG) in lipid bodies. Studies on lipid transport into lipid bodies are essential for elucidating mechanisms of lipid body formation. We used fluorescent dyes and fluorescent lipid analogs to visualize lipid body formation with a confocal laser scanning microscope. Different sizes of lipid bodies ... More